CEN - EN 1992-4
Eurocode 2 - Design of concrete structures - Part 4: Design of fastenings for use in concrete
|Publication Date:||1 September 2018|
|ICS Code (Concrete structures):||91.080.40|
|ICS Code (Technical aspects):||91.010.30|
This European Standard provides a design method for fastenings (connection of structural elements and non-structural elements to structural components), which are used to transmit actions to the concrete. This design method uses physical models which are based on a combination of tests and numerical analysis consistent with EN 1990:2002, 5.2.
Additional rules for the transmission of the fastener loads within the concrete member to its supports are given in EN 1992-1-1 and Annex A of this EN.
Inserts embedded in precast concrete elements during production, under Factory Production Control (FPC) conditions and with the due reinforcement, intended for use only during transient situations for lifting and handling, are covered by CEN/TR 15728.
This EN is intended for safety related applications in which the failure of fastenings may result in collapse or partial collapse of the structure, cause risk to human life or lead to significant economic loss. In this context it also covers non-structural elements.
The support of the fixture can be either statically determinate or statically indeterminate. Each support can consist of one fastener or a group of fasteners.
This EN is valid for applications which fall within the scope of the EN 1992 series. In applications where special considerations apply, e.g. nuclear power plants or civil defence structures, modifications can be necessary.
This EN does not cover the design of the fixture. Rules for the design of the fixture are given in the appropriate Standards meeting the requirements on the fixture as given in this EN.
This document relies on characteristic resistances and distances which are stated in a European Technical Product Specification (see Annex E). At least the characteristics of Annex E are given in a European Technical Product Specification for the corresponding loading conditions providing a basis for the design methods of this EN.
Type of fasteners and fastening groups
This EN uses the fastener design theory1) (see Figure 1.1) and applies to:
a) cast-in fasteners such as headed fasteners, anchor channels with rigid connection (e.g. welded, forged) between anchor and channel;
b) post-installed mechanical fasteners such as expansion fasteners, undercut fasteners and concrete screws;
c) post-installed bonded fasteners and bonded expansion fasteners.
For other types of fasteners, modifications of the design provisions can be necessary.
This EN applies to fasteners with established suitability for the specified application in concrete covered by provisions, which refer to this EN and provide data required by this EN. The suitability of the fastener is stated in the relevant European Technical Product Specification.
This EN applies to single fasteners and groups of fasteners. In a group of fasteners, the loads are applied to the individual fasteners of the group by means of a common fixture. In a group of fasteners, this European Standard applies only if fasteners of the same type and size are used.
The configurations of fastenings with cast-in place headed fasteners and post-installed fasteners covered by this EN are shown in Figure 1.2.
For anchor channels, the number of anchors is not limited.
Post-installed ribbed reinforcing bars used to connect concrete members are covered by a European Technical Product Specification.
Fastener dimensions and materials
This EN applies to fasteners with a minimum diameter or a minimum thread size of 6 mm (M6) or a corresponding cross section. In case of fasteners for fastening statically indeterminate non-structural systems as addressed in 7.3, the minimum thread size is 5 mm (M5). The maximum diameter of the fastener is not limited for tension loading but is limited to 60 mm for shear loading.
EN 1992-4 applies to fasteners with embedment depth hef ≥ 40 mm. Only for fastening statically indeterminate non-structural systems as addressed in 7.3 fasteners with effective embedment depth of at least 30 mm are considered, which may be reduced to 25 mm in internal exposure conditions. For fastenings with post-installed bonded fasteners, only fasteners with an embedment depth hef ≤ 20d are covered. The actual value for a particular fastener may be found in the relevant European Technical Product Specification.
This EN covers metal fasteners made of either carbon steel (EN ISO 898-1 and EN ISO 898-2, EN 10025-1, EN 10080), stainless steel (EN 10088-2 and EN 10088-3, EN ISO 3506-1 and EN ISO 3506-2) or malleable cast iron (ISO 5922). The surface of the steel can be coated or uncoated. This EN is valid for fasteners with a nominal steel tensile strength ≤ 2 fuk 1 000 N / mm . This limit does not apply to concrete screws.
Loading on the fastenings covered by this document can be static, quasi-static, fatigue and seismic. The suitability of the fastener to resist fatigue and seismic loadings is specifically stated in the relevant European Technical Product Specification. Anchor channels subjected to fatigue loading or seismic loading are not covered by this EN.
The loading on the fastener resulting from the actions on the fixture (e.g. tension, shear, bending or torsion moments or any combination thereof) will generally be axial tension and/or shear. When the shear force is applied with a lever arm a bending moment on the fastener will arise. EN 1992-4 considers axial compression on the fixture only when it is transmitted to the concrete either directly to the concrete surface without acting on the embedded fastener load transfer mechanism or via fasteners suitable for resisting compression.
In case of anchor channels, shear in the direction of the longitudinal axis of the channel is not covered by this EN. NOTE Design rules for anchor channels with loads acting in the direction of the longitudinal axis of the anchor channel can be found in CEN/TR 17080, Design of fastenings for use in concrete - Anchor channels - Supplementary rules.
Design of fastenings under fire exposure is covered by this EN (see informative Annex D).
Concrete strength and type
This EN is valid for fasteners installed in members made of compacted normal weight concrete without fibres with strength classes in the range C12/15 to C90/105 all in accordance with EN 206. The range of concrete strength classes in which particular fasteners may be used is given in the relevant European Technical Product Specification and may be more restrictive than stated above.
Concrete member loading
In general, fasteners are prequalified for applications in concrete members under static loading. If the concrete member is subjected to fatigue or seismic loading, prequalification of the fastener specific to this type of loading and a corresponding European Technical Product Specification are required.